Operation Manual – DHCPH3C S7500 Series Ethernet Switches Chapter 4 DHCP Snooping Configuration4-5II. Enabling DHCP-Snooping option 82Follow these steps to enable DHCP-snooping option 82 on a DHCP-snooping-enablednetwork device:To do… Use the command… RemarksEnter system view system-view —Enable DHCP-Snoopingoption 82dhcp-snoopinginformation enableRequiredThis function is disabledby default4.3 Displaying and Maintaining DHCP SnoopingTo do… Use the command… RemarksDisplay the IP-MAC mappingsrecorded by theDHCP-Snooping-enabled switchdisplay dhcp-snoopingDisplay DHCP-Snooping statusand trusted port information display dhcp-snooping trustDisplay the total number ofDHCP-Snooping binding tableentriesdisplay dhcp-snooping countDisplay the DHCP-Snoopingbinding table entries of thespecified VLANdisplay dhcp-snooping vlan{ vlan-list | all }Available inany viewClear the IP-MAC mappingsrecorded by theDHCP-Snooping-enabled switchreset dhcp-snooping[ ip-address ]Available inuser view4.4 DHCP Snooping Configuration ExampleI. Network requirementsAs shown in Figure 4-3, the Ethernet 2/0/1 port of Switch A is connected to Switch B(acting as a DHCP relay agent). A network segment containing some DHCP clients isconnect to the Ethernet 2/0/2 port of Switch A.z The DHCP snooping function is enabled on Switch A.z The DHCP-Snooping-enabled device supports option 82 and option 82 is enabledon the switch.z The Ethernet 2/0/1 port of Switch A is a trusted port.
